thierryc/glyphs-mcp/glyphs-mcp-opentype-features

Glyphs OpenType Features

Start from the requested feature, font source and workspace. Use the focused native feature workflow for review, source changes or compiler diagnostics. Creating or reviewing a script needs no open Glyphs document, MCP connection or document discovery.

For updating Glyphs-managed automatic prefixes, classes and features, prefer the advertised native_action named update_features and follow the closed native-action contract. Its native updateFeatures() call includes Glyphs' automatic update/compilation behavior; inspect the generated source and diagnostics before acceptance.

For compiler-only evidence, use the advertised closed feature_compile job and feature-compilation workflow. For a generated binary or feature-on/off behavior, use the advertised font_export job and verified export workflow. These remain inside the same twenty-tool surface and do not expose arbitrary code.

For manual source edits or coordinated changes across prefixes, classes and features, offer direct native scripting under the shared script contract. Use one whole script with exact block names, expected old text and replacement text in params; no artificial layer target is needed. Native script recovery restores the detached pre-run font copy, including unsaved feature source and other in-font data. Restore before run discards later unsaved edits and clears Undo history. Keep collection order and automatic/manual state intact. A few related blocks can justify this route; the surface-count threshold does not apply to features. Compilation, export and shaping remain separate evidence; MCP diagnostic and artifact lifecycles differ from scripts. Never replace a missing advertised update_features capability with an implicit script.

Reuse the target, workspace and relevant references already in context. For needed live MCP reads, retain the connection's document ID through document targeting. An isolated native runner needs its own explicit source path; it does not share that live document or its unsaved changes.